class Ninja {
    constructor(name, level) {
        this.name = name || 'ninja'
        this.level  = level || 1
    }
    swingSword() {
        return true
    }
    static compare(nin1, nin2){
        return nin1.level - nin2.level
    }
}

let ninja1 = new Ninja('yo', 4)
let ninja2 = new Ninja('yo', 3)
console.log('compare' in ninja1)
console.log(ninja1)
console.log(Ninja.compare(ninja1, ninja2))
console.log('swingSword' in Ninja)


class Person {
    constructor(name) {
        this.name = name
    }
    dance() {
        return true
    }
}
class personto extends Person {
    constructor(name, weapon){
        super(name)
        this.weapon = weapon
    }
    wieldWeapon(){
        return ture
    }
}

let person = new Person('Bob')
